This International Standard specifies a method for determining the benzoic acid content of fruits, vegetables and derived products. As chlorobenzoic acids are resistant to oxidation, the method cannot be applied in the presence of p-chlorobenzoic acid, as the absorption spectrum of this acid is close to that of benzoic acid. Neither can it be used in the presence of cinnamic acid, which is transformed into benzoic acid by chromic acid oxidation. NOTE The cinnamic acid determined as benzoic acid in this method exists generally only in the form of traces in vegetables, and therefore has no effect on the result obtained, except in the case of cinnamon bark, which contains higher quantities.